From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:50620)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1TLwNX-00072U-50
	for qemu-devel@nongnu.org; Wed, 10 Oct 2012 09:31:19 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1TLwNP-0007ax-Au
	for qemu-devel@nongnu.org; Wed, 10 Oct 2012 09:31:15 -0400
Received: from mail-da0-f45.google.com ([209.85.210.45]:34328)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1TLwNP-0007aq-4J
	for qemu-devel@nongnu.org; Wed, 10 Oct 2012 09:31:07 -0400
Received: by mail-da0-f45.google.com with SMTP id n15so176663dad.4
	for <qemu-devel@nongnu.org>; Wed, 10 Oct 2012 06:31:06 -0700 (PDT)
Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <50757894.2000703@redhat.com>
Date: Wed, 10 Oct 2012 15:31:00 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1348577763-12920-1-git-send-email-pbonzini@redhat.com>
	<20121008113932.GB16332@stefanha-thinkpad.redhat.com>
	<5072CE54.8020208@redhat.com>
	<20121009090811.GB13775@stefanha-thinkpad.redhat.com>
	<877gqzn0xc.fsf@codemonkey.ws> <50743D91.4010900@redhat.com>
	<87391n8xmq.fsf@codemonkey.ws> <5074502F.5030706@redhat.com>
	<87ehl7lcxu.fsf@codemonkey.ws> <50751FAB.1000201@redhat.com>
	<87haq2ldjr.fsf@codemonkey.ws>
In-Reply-To: <87haq2ldjr.fsf@codemonkey.ws>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] Block I/O outside the QEMU global mutex was "Re:
 [RFC PATCH 00/17] Support for multiple "AIO contexts""
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Anthony Liguori <aliguori@us.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@gmail.com>, Ping Fan Liu <pingfank@linux.vnet.ibm.com>, qemu-devel@nongnu.org, Avi Kivity <avi@redhat.com>

Il 10/10/2012 14:25, Anthony Liguori ha scritto:
>> > NBD uses coroutines; curl can use the non-unlocked
>> > bdrv_aio_readv/writev.  In both cases they would execute in the
>> > dataplane thread.  qcow2-over-raw would also execute its read/write code
>> > entirely from the dataplane thread, for example.
> Does that mean that we'd stop processing the queue if we're waiting for
> an I/O completion to handle meta data operations?
> 
> If that's the case, that probably will hurt performance overall.

>>From discussion on IRC it looked like this was ENOCAFFEINE. :)

Paolo